Sv.2 suid bits and shell scripts

Alexis Dimitriadis alexis at reed.UUCP
Fri Nov 29 19:29:45 AEST 1985


re `interpreter' is most often "/bin/sh" or "/bin/csh".  The _kernel_
regognizes this, and starts the specified interpreter,  setting its
effective uid if the script is setuid.  Use at your own risk.

Bonus for 4.2 types:
  A single argument may follow the `interpreter' name, if it is
separated by exactly one space (aaargh..).  This makes it possible to
write an awk or sed script, say `foo', and run it by typing `foo',
without the overhead of exec'ing a shell, like this:

#! /bin/awk -f 
(awk commands here)

The kernel tacks the filename at the end, so awk sees

	/bin/awk -f /u/ss/alexis/bin/foo

and everything is peachy.  This is a really handy trick that I have not
seen used before, so I thought I'd throw it in.

Alexis Dimitriadis
-- 
_______________________________________________
Any opinions expressed above have been grown organically and contain
no preservatives or artificial sweeteners.

				alexis @ reed
    {decvax,ihnp4,ucbcad,uw-beaver}!tektronix!reed.UUCP



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